1, 2, 3
1, 2, 3, 1, 12, 14, 15, 16, 18, 19, 2, 20, 21, 23, 24, 25, 26, 29, 3, 30, 32, 33, 34, 35, 36, 37, 38, 39, 4, 40, 42, 43, 44, 45, 47, 49, 5, 50, 53, 6, 7, 8